Conventional methods for performing high throughput mass spectrometric (MS) protein identification employ either 2D-PAGE technology or various modes of multidimensional chromatography. 2D-PAGE is commonly used in proteomics (i.e., the study of proteins). In a typical 2D-PAGE process, 3000 to 5000 different proteins can been separated. After separating, spots of the separated proteins can be cut out and analyzed using mass spectrometry.
Conventional 2D-PAGE technology, however, has a number of drawbacks. Drawbacks include low sensitivity (e.g., 1 ng protein detection limit with silver staining), the limited range of proteins that can be analyzed, (membrane proteins, high molecular, low molecular proteins are underrepresented), and low sample throughput. The low sample throughput is due to the labor and time intensiveness of this method. For example, 2D-PAGE systems allow for the processing of only 10 gels in two days per system. In order to take advantage of MS, additional equipment (e.g., robotic gel spot cutters and digest workstations) is required. Besides being complex and costly, these automated systems are not generally suited to identify low abundance proteins.
Other chromatographic methods based on multidimensional chromatography (e.g., LCxe2x80x94LC) may offer faster analysis cycles. However these methods have limitations including low detection limits and the limited scope of proteins that may be analyzed (e.g., due to solution condition limitations imposed by the selected chromatographic method).
Embodiments of the invention address these and other problems.
One embodiment of the invention is directed to a microanalysis chip comprising a body defining at least one transfer-separation channel including a channel bottom having a bottom opening, the transfer-separation channel terminating in a discharge aperture.
Another embodiment of the invention is directed to a method for chemically affecting a sample, the method comprising: providing a microanalysis chip including a body having a transfer-separation channel with a channel bottom having a bottom opening; inserting a pillar into the bottom opening such that a sample supported by the pillar communicates with the transfer-separation channel; and passing a reagent fluid into the transfer-separation channel in order for the reagent fluid to come in contact with the sample to chemically affect the sample.
Another embodiment of the invention is directed to a dispenser assembly comprising: a dispenser chip including a dispenser body including a vertical channel; and a sample chip having a base and a sample structure, the sample structure comprising a pillar and a sample surface, wherein the vertical channel of the dispenser chip is cooperatively structured to receive the pillar.
Another embodiment of the invention is directed to a microfluidic chip comprising: a body having a bottom surface; a plurality of discharge apertures; and a plurality of transfer-separation channels in the body, each transfer-separation channel defined by a channel bottom with a bottom opening, and having a portion upstream of the bottom opening and a portion downstream of bottom opening, and wherein each transfer-separation channel terminates at one of the discharge apertures.
Another embodiment of the invention is directed to a microfluidic assembly comprising: a microfluidic chip comprising (i) a body having a bottom surface, (ii) a plurality of discharge apertures, and (iii) a plurality of transfer-separation channels in the body, each transfer-separation channel defined by a channel bottom with a bottom opening, and having a portion upstream of the bottom opening and a portion downstream of bottom opening, and wherein each transfer-separation channel terminates at one of the discharge apertures; and a sample chip comprising a base including a non-sample surface and a plurality of sample structures having a plurality of sample surfaces.
Another embodiment of the invention is directed to a method of processing an analyte, the method comprising: processing an analyte on a sample surface on an sample chip; transferring the processed analyte through a transfer-separation downstream of the sample surface, wherein the transfer-separation channel is in a microfluidic chip above the sample chip; and analyzing the processed analyte downstream of the sample surface.
Another embodiment of the invention is directed to a microfluidic chip comprising: a body having a bottom surface; and a plurality of vertical channels in the body, wherein each opening is cooperatively structured to receive a pillar of a sample chip.
Another embodiment of the invention is directed to a method of processing analytes, the method comprising: inserting a plurality of sample surfaces into a plurality of vertical channels in a dispenser chip, wherein the plurality of sample surfaces are on pillars of a sample chip; depositing a plurality of liquid samples on the sample surfaces while the sample surfaces are in the vertical fluid channels; binding analytes from the plurality of liquid samples to the sample surfaces; withdrawing the sample surfaces from the vertical fluid channels; inserting the plurality of sample surfaces into a plurality of openings in a microanalysis chip so that the plurality of sample surfaces are in communication with a plurality of transfer-separation channels in the microanalysis chip; and processing the analytes using reagents flowing through the transfer-separation channels while the analytes are bound to the sample surfaces.
Another embodiment of the invention is directed to an analysis system comprising: an analysis assembly comprising (i) a microanalysis chip comprising a body comprising at least one transfer-separation channel defined by a channel bottom having a bottom opening, the transfer-separation channel terminating in a discharge aperture, and (ii) a sample chip having a plurality of sample surfaces; and an analysis device adapted to receive an analyte from the discharge aperture.
These and other embodiments of the invention are described with reference to the Figures and the Detailed Description.